Vernier adjustment means for electrical instruments



March 29 9 19276 Filed Dec. 1924 M WW Y W T m T H A m. N v: 5 \km 1 b Mm Patented Mar. 29, 1927. UNITED STATES NICHOLAS HEYMAN, OF BUFFALO, NEWYORK,

MANUFACTURING CORPORATION, NEW YORK.

ASSIGNOR TO FEDERAL TELEPHONE OF BUFFALO, NEW YORK,,A CORPORATION OFVERNIER ADJUSTMENT MEANS FOR ELECTRICAL INSTRUMENTS.

Application filed December 19, 1924. Serial No. 756,895.

This invention relates to adjustment means for such electricalinstruments as require foreflioient operation the coarse and rapidadjustment of certain elements of the aparatus relatively to each otherfollowed y a fine adjustment of said elements. More particularly theinvention relates to adjustment means of this character adapted to usewith variable condensers such as used in radio systems. 7 Y

It is the object of the invention to provide an improved Vernieradjustment means to be attached to a shaft such as that for examplewhich actuates the movable plate assembly of a condenser, the adjustmentmeans being so constructed that a rapid and coarse adjustment of themovable plates is made as usual by means of a dial or other controlmember, While a fine adjustment through a small number of degrees ismade by means of a knob or other control member mounted upofii thecontrol dial and concentric there wit In accomplishing this object, thedial or other main control member is fixed in any usual manner to theshaft element which actuates the movable plate assembly of thecondenser. The Vernier knob is rotatable in the dial member and carriesan extension which. isprovided with an actuating member such as a cam atits inner end. The cam actuates a lever formed to act as a cam followerand pivoted at one end to the dial member. The other end of the lever ispivoted to resilient means with relation to which the dial and shaft arerotatable through a \small angle and which is arranged to bear withconsiderable pressure on the surface of a fixed member, such as a panelon which the condenser may be mounted. The coarse adjustment is made byturning the'dial with its attached shaft member and movable plates, theresilient means being carried around with the dial and sliding overthesurface of the panel, While the fine adjustment is'made by turningthe Vernier knob and its attached cam. The cam moves the pivoted lever,and since this lever is ivoted at one end to the resilient means, whichbear strongly against the panels and which remain in place except when aturning force is exerted on the dial, as in the operation of coarseadjustment, the lever swings about its pivoted connection on theresilient means as the Vernier knob is rotated and thereby moves themain dial, with its attached shaft and plates, through a small angle.

For a clearer understanding of the con mode of operation related partsof the embodiment shown in these operat Fig. 1. The sectional view of mgparts as shown in Fig. 1 is AA of Fig. 2.

The main control member comprises preferably a dial 1 of the formcommonly used in radio receivers and a cup shaped member 2to which thedial is secured, as by screws 3. A shaft member 4 is riveted orotherwise fixed. to cup member 2. A condenser 5 is fastened in anypreferred manner to a fixed member as panel 6. The shaft 7 which carriesthe movable plates 8 of the condenser is connected to the shaft member 4as by set screw 9.

A resilient member 10 preferably in the form of a spring plate islocated within cup shaped member 2, with contact faces 11 resting on thesurface of panel 6. Spring plate 10 is rigidly fixed to a bracket member12 as by rivets 13. The bracket member is placed on the opposite side ofcup shaped member 2 from s ring plate lO-and is rov'idedwith inward yprojecting arms 14w ich pass through openings 15 in the cup member inorder to make connection with the spring plate. A lever 16 having acentrally disposed opening 17 is pivoted as by rivet 18 to the innerside of bracket 12. The lever extends across the center of the apparatusand its other end is connected to the cup member 2 as by rivet 19, theform of connection being such that provision is made for a slight motionof the lever in the direction of its length, as by slot 20 in whichrivet 19 bears.

vernier control member or knob 21 comtaken on line prises preferably amain portion 22 of in-:

a bearing centrally in dial 1, preferably in a metal insert 24 mouldedin the dial. An

extension of the vernier member or knob 21 is provided which comprisesan actuating member such as a cam 25 at the inner end of a stub shaft26. This stub shaft which carries the cam is centrally located in theknob and rigidly fastened therein as by set screw 27 which passesthrough the wall of insert 23. The stub shaft passes through a centrallydisposed opening 28, in bracket 12. The cam 25 is located betweenbracket 12 and cup 2 and projects within the centrally disposed opening17 formed in lever 16. The lateral edges 29 of opening 17 are preferablyformed parallel to a line drawn between pivotal points 18 and 19 of thelever, although they may be formed with other contours if desired. Cam25 and the edges 29 of the opening 17 are so disposed and dimensionedthat said cam is maintained in close working contact with the lever atall positions of the cam.

It will be seen that Fig.2 is a plan view of the operating parts of thedial and vernier knob assemblies with the knob 21 removed from shaft 26and also with the dial 1 removed from cup 2. It is clear from a thisfigure and also from Fig. 1 that the construction consists essentiallyof two distinct parts: the dial assembly and the vernier controlassembly. The former comprises shaft 4, cup 2 and dial 1, when said dialis mounted on the cup. The latter comprises the rigidly connected springplate 10 and spring bracket 12, vernier knob shaft 26 with its bearingin the bracket, and vernier knob 21 to its shaft 26. Theconrigidlyconnected necting link between the dial assembly and the vernier knobassembly may be considered to be lever 16 pivoted at one end to thespring bracket 12 and at' the other to the dial cup 2. The vernier knobassembly further comprises the actuating member or cam 25 which coactswith lever 16, and which also, since it is located between cup 2 andbracket 12 which are connected by lever 16, serves to hold the vernierknob assembly within the dial assembly.

In the operation of the invention, adapted, as in the constructiondescribed, to be employed as the adjustment means for a radio condenser,IOt-iltlOIl of dial 1 effects the initial coarse adjustment of theapparatus in the usual manner, since the dial is rigidly connectedthrough cup member 2 and shaft 4 to the movable plate assembly 8 of thecondenser. In this tuning operation, the spring plate 10 and all otherparts of the apparatus mounted within or on the dial move together withthe dial, the contact faces 11 of the spring plate 10 sliding over theface of the panel 6 when the moderate amount of force required to turnthe dial against this friction is applied. Further, during thisoperation of coarse adjustment, the vernier knob 21 maintains itsrelation to the dial 1 unchanged, since with the small throw of cam 25required in practice, the pressure transmitted from the dial to lever 16through cup 2 and pivot 19, and acting on a cam at an edge 29 of theopening 17, is not sufficient to turn the cam about its shaft,regardless of the position in which the cam may be with reference to thelever.

After this coarse adjustment of the condenser the final criticaladjustment is accomplished by turning the vernier knob rigidly connectedto cam 25 which acts upon lever 16. The center of rotation of this lever16 is pivot. 18 which is located on the spring bracket 12. The bracket12, spring plate 10 and pivot 18 remain fixed 1n position during thevernier adjustment operation because of the pressure exerted by thespring plate contact surfaces 11 against the panel 6. WVith one end ofthe lever pivoted at the fixed point 18, the other end of the leverswings about this fixed point as the cam is turned by the knob. As thisfree end is loosely coupled at rivet 19 to the cup 2 which is fastenedto the dial and to the shaft 1, therefore, these latter parts, togetherwith the movable condenser plate assembly 8 connected to shaft 1, arerotated through a small angle as knob v21 is turned. In Fig. 2 the camis shown as turned half-way from the extreme throw in one direction tothe extreme throw in the other direction. It

is evident from the figure-that a clockwise movement of the cam by knob21 through approximately ninety degrees will result in a shift of thecup 2, dial 1, shaft 1 and condenser movable late assembly 8, through asmall angle in t 1e clockwise direction, and that a counter-clockwisemovement of the cam will likewise result in a correspondingcounterclockwise movement of these adjustable parts. The adjustmentmeans may be so proportioned as to produce any desired small degree ofangular movement of the dial and condenser plates corresponding to thethrow of the cam. For example, in the embodiment of the invention asapplied to the vernier adj ustmcnt of a radio condenser, the cam andlever action may be proportioned to produce three degrees of dialmovement corresponding to a rotation of the vernier knob ofapproxnnatcly one hundred and eighty degrees, or a reduction, for lineadjustment purposes, in the ratio of sixty to one.

What is claimed is:

1. In. an adjustment control apparatus, a

ly, and a second control member adapted to thereto, a resilient membersli'dable on thefixed member, the shaft being rotatable relative to theresilient memb member fixed to theshaft, a lever ivoted at its ends tothe resilient member an to the main control member respectively, and asecond control member comprising a cam coactingwith the lever to movethe main control member and the shaft member relative tolthe fixedmember,

3. In an adjustment control apparatus, a fixed member, a shaft rotatablerelative thereto, a resilient member'slidable on said fixed member, theshaft being rotatable relative to the resilient member, a main controlmember fixed to the shaft, a lever pivoted at its ends to the resiltentmember and to the main control member respectively, and a second controlmember concentric with the main control member and adapted to coact withthe lever to move the main control member and the shaft relative to theresili' ent member and the fixed member.

4. In an adjustment control apparatus, a fixed member, a shaft rotatablerelative thereto, a resilient member slidable on the fixed member, theshaft being rotatable relative to the resilient'member, a main controlmember fixed to the shaft, a lever pivoted at its ends to the resilientmember and to the main control member respectivel and a second controlmember concentric with the main control member coacting with the leverto move the main control member and the shaft member relative to thefixed member.

5. In an adjustment control apparatus comprisin a fixed member and amain control member .rotatable relative thereto, a resilient memberadapted to be held stationary relative to'the fixed tional engagementtherewith, means interconnecting said main control member and saidresilient member, said means comprising a lever pivoted at its ends totheresilient member and to the main control member respectivel and asecond rotatable control member: a aptedto swin the lever about itspivoted connection with the stationary resilient member, whereby themain control member is rotated throu h a small angle relative tothefixed mem er as the second control member i's rotated.

.6. In 'an adjustment control apparatus trol member rotatable resilientmember adapted .to be held stationer, a main control and comprising acam.

member by fric-' nection with comprising a fixed member and a mainconrelative thereto, a

ary relative to the fixed member by frictional engagement therewith,means interconnecting said main control member and sa1d resilientmember, ing a lever pivoted at ent member and to the its ends to theresilima n control member said means comprisrespectively, and a secondrotatable control member comprising a cam coacting with the lever,whereby the lever is swung about its pivoted connection with thestationary resilient member as the second control member is rotated andwhereby the main control member is rotated through a small anglerelative to the fixed member.

In an adjustment control apparatus comprising a fixed member and a maincontrol 'member rotatable relative thereto, a resilient member adaptedto be held stationary relative to the fixed member by frictionalengagement therewith, means interconnecting said main control member andsaid resilient member, said means comprisinga lever pivoted at its endsto the resilient member and to the main control member respectively, anda second rotatable control member comprising an actuating membercoacting with bearing faces formed in the lever, whereby the lever isswung about its pivoted connection with the stationary resilient memberas the second control member is rotated'and' whereby the main controlmem her is rotated through. a small angle relative to the fixed member.

8. In an adjustment control apparatus comprising a fixed member and amain control member rotatable relative thereto, a

resilient member adapted to be held stationary relative to the fixedmember byfrictional engagement therewith, means interconnectin said maincontrol member and said resilient member, said means comprising a leverpivoted at its ends to the resilient member and to the main controlmember respectively, and a second rotatable control member concentricwith the main control member and comprising a cam coacting with bearingfaces formed in the lever, whereby the lever is swung'about its pivotedconthe stationary resilient member as the second control member isrotated and whereby the main control member is rotated through a smallangle relative to the fixed member.

In witness whereof, I hereunto subscribe my name.

' NICHOLAS HEYMAN.

